Tag: ecosystems

Clunky, clumsy, and slow–these are the words that some scientists have associated with Tyrannosaurus rex in the past decade, using these physical traits as evidence that it was more of a scavenger than a hunter. But another group of researchers has held to the notion of T. rex as a fierce predator worthy of the name “tyrant lizard king.” It’s a debate that just won’t go extinct, and this week brings an interesting new argument for the predator position.

In the past several years, scientists have pointed out that T. rex had small eyes and a good sense of smell, and have argued this as evidence that it was a scavenger.

“It’s a jungle out there,” you might hear a big shot Wall Street type say about the high-stakes world of high finance. Yet, the jungle-ecosystem metaphor may be most applicable not to the competitiveness of the world’s financial system, but to its vulnerability.

For an unusual study in this week’s edition of the journal Nature, an economist (Andrew Haldane of the Bank of England) and a zoologist (Robert May of Oxford University) team up to argue that the banking and financial system is much like a natural system in the way that a key hit to one area caused the cascading wave of doom, which wrecked the world economy in 2008.

One way to see the resemblance is to think of the world’s many banks as the bean plants in a vast industrial mega-farm, where the nearly identical plants are all vulnerable to the same pest.

When a biological or social system is full of uniform individuals—be they bean plants or banks—one shared weakness can spell disaster for the whole lot. Even when a new beneficial trait or tool enters the picture, if all organisms adopt it, as many financial institutions did with credit default swaps and other risky trades that led to the financial meltdown of 2007-08, a tenuous balance can be quickly upset. [Scientific American]

Before the collapse, Haldane and May say, the financial sector believed that the high level of connectivity between financial firms was a way to lessen risk. No one firm was at particularly high risk, it was thought, which made it unlikely that any firm would fail. Yet little thought was given to the failure of the system as a whole.

The oceans are getting louder and forcing some whale to speak up, according to a study published yesterday in the journal Biology Letters.

Lead researcher Susan Parks of Penn State University eavesdropped on seven male and seven female North Atlantic right whales by attaching acoustic tags to them via suction cups. Each tag recorded from 2 to 18 calls, which included the whales’ greeting “upcalls” (seemingly questioning “hmm?” sounds that go from a low to high pitch — see video), as well as background noise–believed to come from commercial shipping.

Bioacoustics researcher Christopher Clark of Cornell University, who did not participate in the study, says that ocean noise is becoming a serious issue.

“If I had to immerse you into the sea off Boston, you’d be shocked. You’d be like a country mouse dropped in the middle of Heathrow Airport,” says Clark. “In one generation, we have raised the background level for an entire ocean ecosystem.” [New Scientist]

Sure, the planet’s increasing carbon dioxide levels are making the oceans more acidic, but what does that really mean for sea life? We’ve already heard that the ocean’s changing chemistry is damaging corals and interfering with mussels, but that’s just the beginning. It turns out things could get seriously weird.

In a paper published this week in The Proceedings of the National Academy of Sciences, researchers led by Philip L. Munday of James Cook University have given us a concrete example: the increased CO2-levels make some fish purposely swim towards predators.

As part of his experiment, Munday used a Y-shaped maze to force baby clownfish to choose between two paths. One path reeked of rock cod, a natural predator; the other had no danger scents. Munday’s team compared the choices of fish raised in water of varying carbon dioxide concentrations, from today’s levels of 390 parts per million up to future expected levels of 850 ppm.

Build a wall of sand: That was Louisiana Governor Bobby Jindal’s answer to protecting the state’s delicate marshlands when it became clear that BP wasn’t going to stop its gushing oil leak anytime soon. But now the federal government has put the kibosh on Louisiana’s construction, saying that the project to save one ecologically sensitive area will ruin another.

Scientists raised several objections to the state’s first proposal last month to build a long line of sand berms on 10 May. One key concern was that taking sand from in front of the Chandeleur Islands would make them more vulnerable to erosion. The state agreed to change its approach by taking sand from a site further away and then pumping it through pipes to build the berms [ScienceNOW].

However, that didn’t happen. Louisiana officials said they couldn’t get the pipes built in time, and asked the feds to let them dredge near Chandeleur at least until the other site was ready. OK, the Interior Department said—you’ve got a week. That week has lapsed, but Louisiana is still requesting more time to dredge near Chandeleur, promising to return the sand once the berm project has done its job.

We have learned of top caps, top kills, junk shots, and dome plans. We have seen President Obama “furious,” standing on the Louisiana shore. Last week, we saw pictures of the immediate victims of the BP oil spill, the Gulf marine life. Pictures that many believe will endure as symbols of the entire spill.

Adding to the impact, the brown pelican is Louisiana’s state bird, and was only recently removed from the endangered species list.

As a senior official of the US Fish and Wildlife Service, James Harris was too diplomatic to say if he thought the anger was justified, but, as a Louisiana native–from Pearl River, north of New Orleans, he pointed out forcefully why it was there, and how the first images of the oiled pelicans had intensified it. “I think it’s possible that they might come to symbolise the whole disaster,” he said. “For the people of Louisiana, the brown pelican is just as much a symbol of the state as the American eagle is for the nation as a whole, and to see the state emblem being threatened again and despoiled–people are very upset and angry about that.” [The Independent]

Over the weekend a huge Chinese freighter loaded down with coal and fuel oil crashed into part of the Great Barrier Reef off the Australian coast. Today, salvage teams are still struggling with how to extricate the Shen Neng 1 without dumping any more of its dirty cargo into the delicate marine ecosystem.

The ship had left the port of Gladstone just a few hours before striking the reef in Douglas Shoal. It ran aground in a restricted zone of the marine park, almost 30km [18.6 miles] from the authorised shipping channels it should have been using [Sydney Morning Herald]. Both the main engine and the rudders sustained serious damage. While rescuers debate how to orchestrate a salvage operation, the Shen Neng 1 has slid another 20 or 30 yards along the reef, destroying more coral in its path.

That seems to have been the starting point for the new nature documentary series LIFE, which spotlights some of the planet’s most gloriously unusual critters. The series, which airs on Sunday evenings on the Discovery Channel, presents animals that belong in the evolution hall of fame. Many have developed remarkable tricks to survive in inhospitable environments, while others have developed fascinating mating rituals that ensure that the fittest individuals pass on their genes, generation after generation.

Click through the gallery for some of our favorite hall-of-famers from the show.

A Restless Trail-Runner

Size does matter, especially for the tiny rufous sengi, an “elephant shrew” whose small size and constant movement makes it hungry—all the time! But movement in a forest full of predators is dangerous, so the sengi devised a clever method to forage for food.

The tiny mammal constructs a series of neatly cleared trails between its regular feeding spots and memorizes their details. Then it launches itself on a trail patrol at breakneck speed, stopping only to check for tasty insects and to clear the trail of any debris. A single twig can be fatal, so the sengi spends up to 40 percent of its time running the trails and clearing away obstacles.

Of all the planet hacking possibilities floated as last-minute ways to stave off a climate catastrophe (building a solar shade for the Earth, injecting the atmosphere with sunlight-reflecting aerosols, etc.), iron seeding seems one of the more practical and feasible ideas. The scheme calls for the fertilization of patches of ocean with iron to spur blooms of plankton, which eventually die, sink, and sequester carbon at the seafloor.

However, worries over the consequences of tinkering with the ocean ecosystem have held up plans to attempt this. And now, in a study in the Proceedings of the National Academy of Sciences, researchers claim that such a plan could risk putting a neurotoxin into the food chain.

Iron seeders have targeted the large swaths of ocean surface with high levels of nitrate and low chlorophyll, where an injection of iron could potentially turn a dearth of plankton into a bloom. But too many phytoplankton can be a bad thing, especially when it comes to members of the genus Pseudonitzschia. This alga produces domoic acid, which it spews into the surrounding seawater to help it ingest iron [ScienceNOW]. Sea lions off California have gotten sick from the toxin. In Canada, three people died in the 1980s from eating shellfish that themselves had eaten Pseudonitzschia.

This week the federal government released its 2010 report, “The State of the Birds,” examining the health of the United States’ native fowl. According to Interior Secretary Ken Salazar, the state of our union’s birds is precarious.

The 2010 report focused on climate in particular. In it, scientists reviewed data for 800 species nationwide, and ranked their sensitivity to climate change based on factors including how many young they produce each year, how able they are to move to new habitats, and how unique their food and nesting needs are [San Jose Mercury News]. Each of the 800 then received a designation of low, medium, or high vulnerability. You can see the methods for scoring here.